Messages in this thread Patch in this message | | | From | "Aneesh Kumar K.V" <> | Subject | [PATCH 3/4] kasan: Don't use kasan shadow pointer in generic functions | Date | Thu, 3 Sep 2015 13:24:22 +0530 |
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We can't use generic functions like print_hex_dump to access kasan shadow region. This require us to setup another kasan shadow region for the address passed (kasan shadow address). Most architecture won't be able to do that. Hence make a copy of the shadow region row and pass that to generic functions.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> --- mm/kasan/report.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 01d2efec8ea4..440bda3a3ecd 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -164,14 +164,20 @@ static void print_shadow_for_address(const void *addr) for (i = -SHADOW_ROWS_AROUND_ADDR; i <= SHADOW_ROWS_AROUND_ADDR; i++) { const void *kaddr = kasan_shadow_to_mem(shadow_row); char buffer[4 + (BITS_PER_LONG/8)*2]; + char shadow_buf[SHADOW_BYTES_PER_ROW]; snprintf(buffer, sizeof(buffer), (i == 0) ? ">%p: " : " %p: ", kaddr); - + /* + * We should not pass a shadow pointer to generic + * function, because generic functions may try to + * access kasan mapping for the passed address. + */ kasan_disable_current(); + memcpy(shadow_buf, shadow_row, SHADOW_BYTES_PER_ROW); print_hex_dump(KERN_ERR, buffer, DUMP_PREFIX_NONE, SHADOW_BYTES_PER_ROW, 1, - shadow_row, SHADOW_BYTES_PER_ROW, 0); + shadow_buf, SHADOW_BYTES_PER_ROW, 0); kasan_enable_current(); if (row_is_guilty(shadow_row, shadow)) -- 2.5.0
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